Small multiverses in fiction.

[Prime32]

There are some highly expansive universes that include massive space travel and also multiple dimensions/timelines or other factors that qualify them as a multiverse, though this is rarely their focus. For example, the Culture Universe includes references to a multiverse, such as the titular Excession, but is primarily concerned with galactic society. A limited universe with both would be very rare, I believe.

Dragonball Super has exactly five timelines, more of which are created by unstable forms of time travel. Each timeline has a set of 12 universes (created in pairs which share the same planets) plus pocket dimensions. Each universe has life on multiple planets, and FTL space travel that can theoretically be used to reach divine realms like Heaven and Hell (they're just very distant regions of space with special properties). Though sometimes it seems like the "universes" are just galactic clusters with incalculable distance between them.

And then spin-offs introduce their own rules so that they can have dozens of extra timelines which don't count as part of the main set.