From what I read, it looks like you confuse two things: people and the organization.
When you talk about team, what are you referring to? In Holacracy, we don't use that word, we have circles (organization's organs with roles inside) and people energizing roles within the organization.
We separate in two spaces: defining the authorities, roles needed by the organization (governance) and assigning people to roles (operations).
We no longer work in “departments” where a team only belongs somewhere. A person can now be assigned to multiple roles across multiple circles, no silos here.
So if your structure is composed of 2 circles with roles inside, them a person could fill roles within the two circles, no problem with that.
Creating a cross link wouldn't be appropriate in this situation.
It is up to the Lead Link of each circle to assign people to roles whereas it is in the governance space of each circle where we define roles (with the Integrative Decision Making process).
Hope that helps,