On vanilla entity product (Bundle type) I have a vanilla grid Bundle products, I need to add the 'open grid in a new tab' (to watch the all grid), I didn't find that option in grid's attributes, is it possible to add that button in this case?
That subgrid ribbon button will get added in the form automatically (next to subgrid “+” button) when you have added the navigation of that associated entity (Product) in parent entity form.
But when I tried this, it didn't work. Around Products there are lot of inline edit grid options and special grids available. This is one of them and you won't get that functionality in associated view or in other regular subgrids. That may be the reason that we are not getting that icon.