An alternative solution, I would use the regex capture similar/same to what ysth did in the first half of his reply, but combine with the useful @ary = $str =~ /(pattern)/g idiom...

use strict;
use warnings;
use Data::Dumper;

my $str = "[x=1 y=3 z=5] {a=1 b=2 c=3} [d=4 e=5 f=6]";

my @ary = map { /(\w+)=(\d+)/g }    # capture foo=bar
          $str =~ /\[([^\]]+)\]/g;  # but only between [ and ]

print Dumper(\@ary);
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