Joining a dataset to a joined dataset

I joined dataset 1 and 2 together. I now want to join dataset 2 and 3 together, since 1 and 3 have no common join clause. Whenever i try to join them together, there is no option to select what dataset to join it too? How do i join dataset 2/3 together, opposed to 1/3?

(Red is what it currently lets me join to, green is what i want to join to)

Hi @HarveyB-B
you can move&drop the dataset 3 on dataset 2.