Trending summary row in line/area chart produces incorrect values when only part of a dimension is in a table

[#1]

Description - When building a freeform table with a subset of a dimension (either using a filter, using display only selected rows, or dropping individual dimension items), if you try to make a line/area visualization that is trended over time from the summary row it uses the entire dimension and not just the items that you've dragged in. This is a problem because it isn't accurately trending the dimension items that you have selected, it is including information that is not in the table and leads to an inaccurate representation. You can see here, with the header/summary row selected, it's trending the entire dimension, because the total for some of the single days in the line graph is greater than the total for the two weeks in the table. 

Why is this feature important to you - This feature is important because when building out trended visualizations, we rely on having accurate information displayed. There are times that we need to trend the sum of a couple items from a dimension, and in some cases using a segment won't work because there is no sub-hit filtering (this is especially important when using product related dimensions). This limits our ability to create useful visualizations within workspace.

How would you like the feature to work - When selecting the summary row (or any row), the associated line/area visualization should display the trended number from the selected row only. If only part of a dimension is in the table (either from a filter or dropping individual dimension items), the visualization should only include data from those items so that the graph matches what is in the freeform table. 

Current Behaviour - Currently when selecting the summary row, it is trending the entire dimension regardless of how many items are displayed in the table.

[#2]

Love this idea! For the longest time I have struggled with problem as well.