While this is not a map, you can find relevant data in the International Telecommunication Union Radio Regulations and precisely in the appendix 30, 30A and 30B (see Volume Two). You will find several tables containing positions that have been allotted to countries. For example Hungary (country code HNG) has a location at 7.5° W (Appendix 30B) and at 12.8° W (Appendix 30A).
However, in this list, you will not find the 4° W for Hungary. This is because countries can ask for additional positions (see article 6 of Appendix 30B about additional systems for example). These positions are not given in the tables and are not (up to my knowledge) available publicly.
One important thing to note is that you can not emit at any frequency from your slot, but only at the frequencies given in the appendixes.