create Expand Collapse(+) in a single column

have you tried matrix visual and set up the stepped layout.

https://learn.microsoft.com/en-us/power-bi/visuals/desktop-matrix-visual?wt.mc_id=DP-MVP-5004616

Hi ak77 

Power bi doesn't support to create expand collapse in single column in table visual currently.

Just as ryan_mayu said that you can consider trying the stepped layout by creating a matrix visual.

Or maybe you can try to use the drill up/down.

Here for your reference:

Drill mode in the Power BI service - Power BI | Microsoft Learn

Best Regards

Zhengdong Xu
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