my $string = "name+C.+city+loc.+loc2+++++++++++++++++++++++++B+++v+G++
++";
$string =~ s/\+(?!\+)|\+{3,}.*$/ /g;
print $string, "\n";
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That will work though it leaves a trailing space.
Why not use split?

my @fields = split /\+/, $string, 6;
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Now @fields[0..4] contain what you want, and the garbage ("BvG") is in $fields[5].

Take it one step further like this:

my $parsed = join " ",(split /\+/, $string, 6)[0..4];
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Do it the hard way with a substitution regexp, or the easy way with split. :)