BAPI_TS_TREE is a standard SAP Structure so does not store data like a database table does. It can be used to define the fields of other actual tables or to process "Direct Subobject of a Project Element" Information within sap ABAP programs. This is done by declaring abap internal tables, work areas or database tables based on this Structure. These can then be used to store and process the required data appropriately. i.e. DATA: wa_BAPI_TS_TREE TYPE BAPI_TS_TREE.
The BAPI_TS_TREE table consists of various fields, each holding specific information or linking keys about Direct Subobject of a Project Element data available in SAP. These include OBJECT_TYPE (Object Category in Project Planning), GUID (Unique Object Key (CHAR32)), EXPLANATION (General Explanation (such as ID or Short Text) of an Object), SUPERIOR_OBJECT_TYPE (Object Category of Superior Object in Project Planning)... See below for full list along with technical details, documentation, text table, check tables, foreign key relationships, conversion routines, relevant tcodes and example ABAP select code etc. .