#!/usr/bin/perl

use strict; # https://perlmonks.org/?node_id=11107038
use warnings;

my %hash;
while( <DATA> )
  {
  my ($prefix, $glob, $value) = split /(?<==)|\s/;
  $hash{$_} = $value for glob $prefix . $glob =~ s/[^:]+/{$&}/gr;
  }
use Data::Dump 'dd'; dd \%hash;

__DATA__
Prefix1=A,B:c,d value1
Prefix2=A:b,c:1,2 value2