Hi Mr.Minemeet…
To answer your question, you would have to dimension your array to the appropriate number of sections to accommodate the numeric values in the TMX file.
Since reading a TMX file would be similar to that of a CSV, you would have to write the code to read a line of that file, separate out the values and then put them into the array properly.
If you are asking if there is a pre-built function to do this, you may try investigating MonoGame.Extended, which I believe supports loading TMX files…