IMPTH 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 "Measuring Point With Hierarchy Level" 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_IMPTH TYPE IMPTH.
The IMPTH table consists of various fields, each holding specific information or linking keys about Measuring Point With Hierarchy Level data available in SAP. These include MANDT (Client), POINT (Measuring Point), MPOBJ (Object Number for the Measuring Point Object), PSORT (Position Number of the Object Measuring Point (Sort Field))... 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. .