Navigation is very easy. Use the drop-down menu at the top to filter your selection. For example, if you want to see only spare parts for the T4, use the drop-down menu in column "XRAY T4" and select "X".
You can do combinations of filters. For example, to see which option parts fit T3 and T1FK'05, use the drop-down menu in columns "T3" and "T1FK'05" and select "O" in both columns. This is only one example of the combinations you can do; there are many other combinations you can choose from to match what you are looking for.