In inputs.conf you'll define the index you want for all of your inputs. In indexex.conf you will define where the index is stored.
homePath = $SPLUNK_DB/yourindex/db
coldPath = $SPLUNK_DB/yourindex/colddb
thawedPath = $SPLUNK_DB/yourindex/thaweddb
maxTotalDataSizeMB = 10000
Then in all of your app searches and reports they will reference your index (start with index=yourindex). There is no way to assign an index to an app that i am aware of similar to how you can assign indexes to roles.
You can put in comments underneath the answers rather than creating a new answer. You create the app, which is only going to have views and dashboards on your index. Then you will create a user role that only has access to that index and give those users access to your app as well.
i want to configure app such that i listens to data from particular index. Objective is to provide users accessing app access data from particular index. what is the other way i can do this.