Using 'map' as a 'grep' :)

#!/usr/bin/perl

use strict; # https://perlmonks.org/?node_id=11143876
use warnings;

my %hash;
@hash{1..26} = 'a' .. 'z';
my %want = map { $hash{$_} =~ /c|x/ ? ($_, $hash{$_}) : () } keys %has
+h;
use Data::Dump 'dd'; dd \%want;
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Outputs:

{ 3 => "c", 24 => "x" }
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