Accessing host and exposing port same time, possible or not?

As of now with Docker for Mac, am I able in the same container to both expose a port and access a service on the host?

Separately, I’m able to do both. But at the same time, I can’t. Seems like I have to decide on having on or the other. I’m asking just to clarify, before moving to a what will be a more laborsome alternative for my use case, hence any comment/insight is much appreciated.

Thanks in advance.