My data looks like below. I have Groups that I share topics each day. We do this randomly based on need.

[![enter image description here](https://i.stack.imgur.com/x8SXB.jpg)](https://i.stack.imgur.com/x8SXB.jpg)

```
|         | Topic 1 | Topic 2 | Topic 3 | Topic 4 | Topic 5 | Topic 6 | Topic 7 | Topic 8 | Topic 9 |
|---------|---------|---------|---------|---------|---------|---------|---------|---------|---------|
| Group 1 |         | 19-apr  | 30-apr  |         |         |         |         |         |         |
| Group 2 | 18-apr  | 25-apr  |         |         |         |         |         |         |         |
| Group 3 |         |         |         |         | 19-apr  | 30-apr  |         |         |         |
| Group 4 | 18-apr  | 25-apr  |         |         |         |         |         |         |         |
| Group 5 |         |         |         |         |         |         | 19-apr  | 30-apr  |         |
| Group 6 |         |         | 25-apr  |         |         |         |         |         |         |
| Group 7 | 18-apr  | 25-apr  |         |         |         |         |         |         |         |

```

For our metrics & analysis, we need a list of groups per date on a different sheet. We like to know which all groups were engaged a given day. Like below

[![enter image description here](https://i.stack.imgur.com/gvwcv.jpg)](https://i.stack.imgur.com/gvwcv.jpg)

Can somebody please help me how I can get this done with only using formulas and without macros?
I believe this can somehow be handled on Index Matching or look-ups.