If you refer to the Database Reference documentation available in the Documentation Library that comes with the product, and look at the BUG table, you will see the definition of the BG_DETECTED_IN_RCYC is
"The RELEASE_CYCLES.RCYC_ID of the release cycle in which the defect was detected."
That tells you the table (RELEASE_CYCLES) that is being cross referenced. If you take the value from the field, and use it to find a record in the specified table with a matching value in the RCYC_ID field, you will find the additional information concerning the Release Cycle.
The ALM UI and report automatically resolve references such as this for you. When you do your own queries, you have to build the query to resolve the references.
"The RELEASE_CYCLES.RCYC_ID of the release cycle in which the defect was detected."
That tells you the table (RELEASE_CYCLES) that is being cross referenced. If you take the value from the field, and use it to find a record in the specified table with a matching value in the RCYC_ID field, you will find the additional information concerning the Release Cycle.
The ALM UI and report automatically resolve references such as this for you. When you do your own queries, you have to build the query to resolve the references.