Let us start with Case, when you check options under "Show Me" filter, here are the options:
In the samples below, we'll login as Maria Ann:
My cases: ONLY cases that you OWNED.
User owned cases: all cases owned by a user (not a queue)
Queue owned cases: all cases owned by a queue (not a user)
My case team's cases: ONLY cases where you are on the Case Team, this NOT includes where users under your role hierarchy added as Case team.
My role-based team's cases: Cases you OWNED & cases owned by all of your subordinates in the role hierarchy.
** this is all cases owned by Maria Ann and her subordinates.
Now, let us look at "Show Me" filter available in Lead, here are the options:
We'll not discuss again for: My leads, User owned leads, Queue own leads, and All leads, but let us see what is the result for My team's lead.
** this is all leads owned by Maria Ann and her subordinates.