Skipping Indefinite tokens

While writing a rule, if a pattern could have indefinite number of any POS tags / chunk tags / tokens between two definite (specific) tokens/tags. Can I get an example of an XML rule to represent such a pattern. I know the empty can map to any kind of token however, if the number of such tokens are also unknown. Is there anything equivalent to ?
Thanks.

I’m not sure I understand the question… This should match A B with anything in between, is this not what you’re looking for?

A B