How to union 3 worksheets to make 1
You won’t be able to make a union of the worksheet. It is advisable to the union on the data itself and then creates the required reports on it.
Still, if your requirements are not fulfilled then what you can do is create 3 separate worksheets and then arrange those in the dashboard. While arranging, keep the header for only 1syt worksheet and hide for the remaining 2. This way, you will be able to create the desired result.