It depends on the interest in question.
Although both my father and I like video games, we usually like very different kinds of them.
All 3 of us love animals and are interested in animals, so that's something we can talk about (particularly my mother and I) and watch programs/ videos of together (all 3 of us). Although only I have turtles as my fave animal, the rest of my family also like turtles.
To some degree we like similar movies and can watch a lot of the same stuff together (particularly horror and thrillers). Of course we all have movies and series that only one of us like, but we can also enjoy a lot of stuff together as we have somewhat similar tastes.
My mother and I are both bookworms and have some shared books we're both into, and we tell each other about the books we read.
All 3 of us like sharing weird stories we've heard (paranormal, conspiracies, mysteries), those are topics we all find very entertaining.
Both my mother and I like board/card /dice games, and we are both relaxed players who are into it for a good and relaxing time, so we play in the same way, all about enjoying ourselves, unlike my father who is all about winning and has to overthink every move he makes.
So we definitely share some interests.
Pokemon is a huge interest of mine that no one is my family share, but reading the manga and playing the games on my own is no problem.
The real problem when I was younger was that they didn't understand about how preoccupied I am with my interests when I have them (especially obsessions), but now that I'm diagnosed, it's less of an issue.