This is possible in very much the same way that you can create a stacked cluster chart in Excel.
E.g if you had 4 metrics that you wanted in clusters two high the following would work by clustering metrics A & B together and C & D together. The blank line is deliberate to split up the columns.
Month Metric A Metic B Metric C Metric D ....
Jan 1 1
- 1 1
-
Feb 1 1
- 1 1
-
Mar 1 1
- 1 1
-
....
You can then assign the range of a stacked chart to the entire range and set data to in columns. Finally set the ‘Marker Gap’ in the appearance tab to 0.
Clusters of any or mixed sizes can be combined. I’ve attached an example.