Scatter and bubble chart need at least two measure, now you are saying , you wanna use X and Y dimension , you could use any aggregate function like count but in the end it has to be numbers on X and Y axis. and I believe if you do that it will not make any sense. What I can suggest you, Use heat map, I am sure you are looking a solution which match with http://branch.qlik.com/#!/project/56728f52d1e497241ae6983e.
here dimension will be on X and Y axis and number will come in pane area.
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