Mac Numbers: How to edit table name directly in Format-Series-Data-Values chart sidebar

In Mac Numbers, how do you get inside a preexisting Value range (what is presented in a bubble in the Format-Series-Data-Value sidebar for charting) to modify the data range?

I have noticed the bubble turns a variety of colors if I keep clicking it. And I can get my cursor inside of the bubble, at the very end of the text contained in the bubble. But the instant I use the left arrow key to attempt to move over and change the text I want to change in the bubble, I get booted out of the bubble and my cursor is now in the space to the right of the bubble I am trying to edit. I thought maybe one of the colors signified it being editable, but it boots me out for every bubble color I try to edit the range in.

I don’t want to have to highlight columns/rows every time I want to apply a new dataset to a formatted chart when all of my data tables are set up the same. I want to be able to go into that range bubble and type over the preexisting table name and have it update that way (after copying the chart over from a sheet with an identically set up data table).

For example, in the snippet I have provided, I want to change the name of the table in the bubble from “Arm” to “Hand”. Everything else stays the same.

The solution within every response semi related to my question that I can find is to highlight the rows and columns of the new data - I find this tedious when a simple table name change to the preexisting value range (within the format-data-value range sidebar) would do the trick.

I have seen with Mac Numbers formulas how there is an option to put the formula into text that gets rid of the bubbles containing range, so I can edit ranges/references within a formula without having to delete those bubbles and retype the full range, but I don’t see anything like that in the chart format sidebar. Maybe the value range bubbles are controlled by a setting I can turn off??

Please note, I get that I can duplicate a preexisting sheet with a data table and chart and paste my new data over the preexisting data so that the chart updates (that's actually how I start). But my charts are usually a work in process, where there is a good chance I will find a modification to my chart template several charts in that I prefer to the previous style, and then I have to go back and replace previous charts with the modified one. Editing the chart value range (in my case, simply the table name) within the formatting sidebar for those previous data tables (all contained on separate worksheets in my file) would save me a headache. Especially given I am usually layering charts within each worksheet (fed by one data table).

Thanks for any help! I must be using the wrong search terms, but I have googled my question every way I can think of in addition to playing around in the spreadsheet trying to figure it out. I have a feeling it is so basic I am going to kick myself when I learn how it’s done (especially given I can't find anyone else online asking about it).