#! /usr/bin/perl

use strict;
use Data::Dumper;

my ( %linked_dsc, $main_var, @actions );

my $maincnt = 0;
my $found = 0;
my ($t1, $t2);
my $contitent_hash = { };

open (FILE, "./Data.txt") or die "Can't find file";

while (<FILE>) {

# From start of 1st 'Main' to start of 2nd 'Main', read the lines and 
# store in appropriate variables
# $contitent_hash has abbreviation as key and full name as value
# @actions has search patterns to look for in the next pass
# for example: 'NA' => 'North America' is in the hash variable and 
#                    'Name = NA' is in the array
    if ( /^Main$/ ) {
        $maincnt++;
    }
    
    if ( $maincnt == 1 ) {
        if ( /^Main/../^End/) {
          if ( /^\s*(.*)\s=\s(.*)/ ) {
              if ( $1 eq "Name") {
                    $main_var = $2;
                    #$linked_dsc{ $main_var } = undef;
                }
          }
       }
        elsif ( /^Sub/../^End/) {    
          if ( /^\s*(.*)\s=\s(.*)/ ) {
              if ( $1 eq "Action") {
                    ($t1, $t2) = split ( /: /, $2 );
                    push @actions, ('Name = '. $t2 );
                    $contitent_hash->{ $t2 } = undef;
                }
                elsif ( $1 eq "Text") {
                    $contitent_hash->{ $t2 } = $2;
                }
          }    
        }
    }
    last if ( $maincnt > 1);
}

# Self checking...
print "---------------------\n";
print "@actions\n";
print "---------------------\n";
foreach my $key ( keys %{ $contitent_hash } ) {
    print "$key = $contitent_hash->{ $key }\n";
    #$linked_dsc{ $main_var }{ $contitent_hash->{ $key } } = undef;
}
print "---------------------\n";
# End of self check

foreach  ( @actions ) {
    
    print "SEARCH STRING: $_\n";
    my (undef, $link_word) = split / = /;
    my ($ret_dsc, $ret_arr ) = process_next( $_ );
    foreach my $key1 ( keys %{ $ret_dsc } ) {
        # Checking...
        print "$key1 = $ret_dsc->{ $key1 }\n";
        $linked_dsc{ $main_var }{ $contitent_hash->{ $link_word } }{ $
+ret_dsc->{ $key1 } } = undef;
    }
    #Checking...
    #print Dumper ( $ret_dsc );
    #print Dumper ( $ret_arr );
}

print Dumper ( \%linked_dsc );


# Subroutine to search for the searchstring in the file, start reading
+ 
# the subsequent lines and store in appropriate variables until the 
# next 'Main' is encountered.
sub process_next {

my $searchstr = shift;

my $new_href= { };
my ( @new_actions, $left_val, $right_val);

seek ( FILE, 0, 0 );

$found = 0;

while ( <FILE> ) {
    
    if ( ! $found ) {
        if ( ! /$searchstr/ ) {
            next;
        }
        else {
            $found = 1;
        }                 
    }
    
    if ( $found ) {
        if ( /^Sub/../^End/) {    
            if ( /^\s*(.*)\s=\s(.*)/ ) {
                if ( $1 eq "Action") {
                        ($left_val, $right_val ) = split ( /: /, $2 );
                        if ( defined $right_val ) { 
                            $new_href->{ $right_val } = undef;  
                            push @new_actions, ('Name = '. $right_val 
+);
                        };
                        #else { print "Not defined\n" };
                    }
                    elsif ( $1 eq "Text") {
                        if (defined $right_val) { 
                            $new_href->{ $right_val } = $2;     
                        }
                        else { 
                            $new_href->{ $2 } = $2 
                        };
                    }
            }    
        }
        last if ( /Main/ );
    }
}

# Checking...
# print "new actions : @new_actions\n";
return $new_href, \@new_actions;
}
[download]

Here is the data file...

Line nos added for reference.. 

1 Main
2  Name = Countries
3 End
4 
5 Sub
6  Action = Find: NA
7  Text = North America
8 End
9
10 Sub
11  Action = Find: EU
12 Text = Europe
13 End
14
15 Main
16  Name = NA
17 End
18
19 Sub
20  Action = Find: US
21  Text = United States
22 End
23
24 Sub
25  Action = Find: CA
26  Text = Canada
27 End
28
29 Sub
30   Action = Find: MX
31  Text = Mexico
32 End
33
34 Main
35  Name = US
36 End
37 
38 Sub
39   Action = 
40  Text = Boston
41 End
42
43 Sub
44   Action = 
45  Text = Atlanta
46 End
47
48 Main
49  Name = EU
50 End
51
52 Sub
53  Action = 
54  Text = France
55 End
56
57 Sub
58  Action = 
59  Text = Italy
60 End
[download]

Output looks as follows:-

---------------------
Name = NA Name = EU
---------------------
NA = North America
EU = Europe
---------------------
SEARCH STRING: Name = NA
US = United States
CA = Canada
MX = Mexico
SEARCH STRING: Name = EU
Italy = Italy
France = France
$VAR1 = {
          'World' => {
                       'Europe' => {
                                     'France' => undef,
                                     'Italy' => undef
                                   },
                       'North America' => {
                                            'Mexico' => undef,
                                            'United States' => undef,
                                            'Canada' => undef
                                          }
                     }
        };
[download]