You can use Slice by Plane to slice Solid/Surface bodies.
As illustrated below, a will operate only on the selected body.

After generating the feature, only the selected body is sliced.

Other Slice feature options:
You can use Slice by Plane to slice Solid/Surface bodies.
As illustrated below, a will operate only on the selected body.

After generating the feature, only the selected body is sliced.

Other Slice feature options: