https://answers.splunk.com/answers/10810/specify-default-index-for-app.html

[samuelaikins]

hi,
I need help on how to set my apps searches to a specific index .so users using the apps will not need to specify the index name in their search.
Any suggestions on this will be very much be appreciated.

Sam

[niketn]

@samuelaikins please try the following:

Settings > Access controls > Roles --> Select Specific Role for which default index needs to be set.

Navigate to option Indexes searched by default and select the index which should be searchable by default.

Set the index(es) that searches default to when no index is specified. User with this role can search other indexes using index= (e.g., "index=special_index").

[p_gurav]

Define your index in default folder i.e customised default indexes.conf