We have created a report pulling data from an Opportunity (Master), Contact and Land (Custom Object with a many-to-many relationship to Opportunities). The schema is as shown below. The "Related by" between Opportunity and Account is "Lookup from what you have", and likewise between Account & Contact. Our report requires data from one of the Land Object Records. The Land Name could be entered against the Opportunity at the time of running.
Has any of the Community successfully reported data against similar requirements and if so would you mind sharing your solution, ideally pausing the report execution to request the Land Name from which to pull fields for inclusion in the report??