How to combine multiple existing Power BI datasets

We are likely targeting a solution that looks like below.   Its not a strong solution as the lineage is a little messy but with the reports now in a common location,  we can move forward with delivering the solution to the intended audience

-in workspace1 create a visual-a
-in workspace2 create a visual-b
-in workspace3 create a visual-c
-'save a copy' of visual-a to workspace4
-'save a copy' of visual-b to workspace4
-'save a copy' of visual-c to workspace4
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-deliver the 3 reports in the workspace4 app as tabs on left menu
OR
-deliver the 3 reports in a dashboard within workspace4