Thank you for writing.
You can refer to our GridView >> Hierarchical Grid
section in the online documentation. Additionally, you can have a look at the Hierarchy of one to many relations
help article demonstrating how to set up two child templates visualized as child tabs under the master row. Thus, after you have the desired child tab it can display the Template which will display your image gallery.
In order to customize the cells you can use the introduced approach in the Formatting Cells
help article. You can pick up the desired Columns
type according to your requirement. If none of the listed cell types suits your scenario, you can create your own cell. The Creating custom cells
help article illustrates a sample approach.
I hope this information helps. Should you have further questions, I would be glad to help.
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