Bitbucket pipeline, different docker image tag based on branch name

[Tim Clephas]

I have a 'main' repository where a docker image is created with a tag idential to the branch name.

I want to use this tag if another repository has the same branch name.

In other words, can the docker image specification dynamically be generated with a simple bash line?

Somethink like:

IMAGE_NAME=dockerhub/image/$BITBUCKET_BRANCH