Part of your problem is that your constructor doesn't do what you think. When you write

my %args = (users => %userHash, domains => %domainHash, path => $path)

Perl sees %userHash and %domainHash in list context, and so it expands them into lists. If your code read

my %userHash = (user1 => 'uid');
my %domainHash = (domain1 => 'uri');
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your %args assignment would actually say

my %args = (users => 'user1',
            uid => 'domains',
            domain1 => 'uri',
            path => $path);
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You need, rather, to use hash refs to maintain the hash structure when you define %args:

my %args = (users => \%userHash, domains => \%domainHash, path => $path);

See perlreftut and/or perllol for information on how to represent nested hash structures (or perldsc or perlref or ...).