Daily and random data. Plot all?

I have two different data sets:

“Levels (m)” which are taken at sporadically rather than continuously. Are grouped. I have a splicer which groups these based on another linked table.

“Stage (m)” which is continuous daily data.

I want to show a particular group of “Levels” data [Monthly -ish random data] and show the corresponding [DAILY] “Stage” data. I have added a calendar table which links to both the data set.

When I select the splicer level data for different groups, the level data shows the points it plots BUT the daily stage data only appears for the dates that appear in the levels data.

I want it to show all the daily stage data between the maximum and minimum dates for the levels data.

Can anyone help? How do I get ALL the stage data to show for the period that matches the stage data.

Group 1

Group 2