$ perl -le 'print $x = "abcdefgxxabcdefgzzabcdsjfhkdfab"; print $1 if $x =~ /(\w{2,})(.*?\1){2}/;'
abcdefgxxabcdefgzzabcdsjfhkdfab
abcd

$ perl -le 'print $x = "abcdefgxxabcdefgzzabcdsjfhkdfab"; print $1 if $x =~ /(\w{2,})(.*?\1){3}/;'
abcdefgxxabcdefgzzabcdsjfhkdfab
ab

$ perl -le 'print $x = "abcdefgxxabcdefgzzabcdsjfhkdfab"; print $1 if $x =~ /(\w{2,})(.*?\1){4}/;'
abcdefgxxabcdefgzzabcdsjfhkdfab