how did you branch out as a FNP?

I like primary care and I'm a FNP, but I think after several years I would like to start part time in a specialty area...there are a handful that interest me.

For those of you who worked in Family Medicine practices, how did you branch out? Was it very difficult? Most of my RN experience was also outpatient primary care, so by then I would be have been RN and FNP in primary care settings only.

I know I could always try networking although most others I meet at professional events are of course also primary care providers. I am not in a hurry but I'd like some idea of how people eventually made the transition, and what they had to do to get there.