Hi Thomas,
Thanks for the answer.
I am using the parameters as filers.
Here are a few screen shots:
the first is the parameter which when I chose account name it changes accordingly:
The second is the way I applied the parameter on the filter (I will say that the filter type was chosen because it was the only one that allowed parameters):
However, after publishing a dashboard it does not work.
I do suspect it is somehow related to site name parameter?. After publishing the parameter of site name does work (as well as in an analysis).
Maybe it is related to the fact our system has an hierarchy in which each account has a number of sites. In order to make things easier I associated between them so when you chose an account only relevant sites appear. As shown here - Relevant values based on filter and recommended by AWS support.