There are little object or setting buttons on image that I added to bottom.
These are showing when I focused the object. This feature generally included all bpmn modelling tools. Is it possible make this with gojs? (BPMN)
If this is possible with gojs, how we can do that?
You are talking about the situation where whenever the user selects a node, that all of those buttons become available.
You can do that with a custom selection Adornment. Please read GoJS Selection -- Northwoods Software and Part | GoJS API.
This sample demonstrates it, although it places the buttons on the top rather than in multiple columns to the right of the Placeholder in the Adornment: Selection Adornment Buttons