Dependency between user stories
We have set of product backlog items planned in the sprint. Couple of stories are dependent on each other. Though the 'INVEST' criteria is applied for the stories as much possible, still there is dependency between priority stories because of the functional flow. Only when one is implemented the other can be started. This sometime causes the developers focusing on scope which will not contribute to achieve the sprint goal in the meantime. What could be possible option here.
Only when one is implemented the other can be started.
Do they both have to be brought into progress at the same time before either can be completed?
That's not the same thing as completing one item first in order to facilitate starting another.
This sometime causes the developers focusing on scope which will not contribute to achieve the sprint goal in the meantime. What could be possible option here.
You just stated a possible option. I work with a lot of teams that will have work in their Sprint Backlog that is not relevant to the Sprint Goal. Often it is fixing a production defect, addressing technical debt, or work on another feature to deliver at another date. No where in the Scrum Guide does it state that all work in the Sprint Backlog has to be attributed to the Sprint Goal. The Sprint Goal is the primary reason for executing the Sprint but it doesn't have to be the only reason.
@Ian Mitchell asks a very valid question. Could it be that you are seeing a dependency that isn't there? Again, teams I've worked with have had backlog items that were less dependent and more reliant on each other.
Only when one is implemented the other can be started.
Stop starting and start finishing. - I see nothing really wrong with that. Your team is limiting WIP.