use 5.12.0;

my $search = '1';

my @AoH = (
    { name => 'bla',  alter =>  9, },
    { name => 'baba', alter => 19, },
    { name => 'foo',  alter => 11, },
);

my @matches;

for my $i ( 0 .. $#AoH ) {

    # add index if searchstring was found in hash values
    push @matches, $i
        if grep { m/\Q$search\E/  } values %{ $AoH[$i] };
}

# print result of search
say "$search matched in elements: @matches";