Can I import several searches into the same list?

Not directly — but you can combine them afterwards, which gets you to the same place.

One import, one list

Each import creates its own list. That is deliberate: a list keeps the search it came from, the filters that were used and its pagination state, and that context is what makes the match figure calculable and lets you compare one search's performance against another's.

Merge two searches at import time and all of that is lost.

Combining them afterwards

Once the imports have finished, move the leads into a shared list of your own:

1. Open the source list and select the leads you want.
2. Choose Move to.
3. Pick an existing list, or create a new one.

Repeat for each source list. The result is one working list built from as many searches as you like, while the originals keep their context.

This is also the natural way to build lists around a theme rather than around a search: one list per campaign, assembled from whichever searches turned up the right people.