#!/usr/bin/perl

use strict; # https://perlmonks.org/?node_id=11142984
use warnings;

$_ = <<END;
        run_type = dev,
        max_monitor_time = 0.25
        verbosity_level = 2

        batch =

            (
                source = sample_document_collection_1
                files = Confucius.docx
                dest = Enterprise:Department
            )
END

my @want = grep defined, /\bbatch =/ && # there is a 'batch ='
  /^(?:\h*batch\s+=[\s\S]*\z  # skip rest of string
    |
    \h*(.*=.*?),?\h*\n)       # the pattern we want
    /gmx;

use Data::Dump 'dd'; dd \@want;