One possible solution to https://www.reddit.com/r/commandline/comments/bu66gt/grepping_or_filtering_chunks_of_treed_output/

section_grep.pl

#!/usr/bin/perl

    use strict;
    use warnings;

    use Data::Dumper;

@ARGV >= 1 or die "syntax:   $0 <pattern> <file1> ...\n";
my $grep_pattern = shift @ARGV;

## break the file into sections
my $accum = '';
while (<>) {
    if (/^.+:$/) {
        if ($accum ne '') {
            process_section($accum);
        }
        $accum = $_;
    } else {
        $accum .= $_;
    }
}

if ($accum ne '') {
    process_section($accum);
}



sub process_section {
    my ($accum) = @_;

    if (eval "\$accum =~ /$grep_pattern/om") {
        print $accum;
    }
}