Linking two of the same data validation lists on two separate sheets

Hi, this is my first post and I am struggling to find a way to link 2 of the exact same data validation lists on two seperate worksheets. For example worksheet one has data and figures for specific regions, and worksheet two provides these figures in a graph, however I would like to link these two worksheets and so if the list is changed in worksheet 1, this will automatically change in worksheet 2 and vice versa. Is this possible? Thanks

That isn't quite what I am looking to do, this is how I have it set up at the moment, however I was wondering if it was possible to change either drop down from either sheet. For example if there are two options in the drop down, "A" and "B", if I selected "A" on sheet 1, I would like it to change to "A" on sheet 2 and vice versa if I selected "B" on sheet 2, I would then like it to change to "B" on Sheet 1.