ssh tunnel: how to connect remotely from a Linux laptop to a Linux home server with ssh

I have been abroad away from home for a prolonged period.
The situation of my home: Ubuntu Desktop, which is the development machine (call it A). It does not have a static IP and is in a home network with many other things, televisions, laptops for children, etc.

There is an application server in another foreign country where I implement the application. Call it B. The implementation is done through ansible, so I have ssh access to remote server B from local machine A.

Now I have a Linux laptop with me (call it C) and I need access to A from C to do an administrative job in A from C as in:
C <----> A

I have read a lot about tunnels and reverse tunnels with SSH and it occurred to me what I think should be possible:

A <----> yes

     B <-----> C (me, overseas) in some way, thus achieving:

A <--------------> C

The problem with the articles I have read that describe something like this configuration uses terms such as server, client, local, remote in a rather ambiguous and confusing way. I am not a network guru, I am perplexed and need help.

Can someone refer me to an article that is clear and unambiguous to describe the use of SSH to do this, or establish the mechanism to achieve it?

I have someone at the end of the home server (A) who can issue an SSH command to the intermediate server (B) (as in port forwarding 22, for example, which could allow my laptop (C) to connect to he (B) in some way).

I don't know what I've left out, so be gentle.