Writing

der die Komplexität des französischen Eisenbahnnetzes und Verwaltung navigierte

sounds a bit incomplete to me. I would suggest an other construction for your sentence. But first let me fix the beginning of your sentence (like Carster Schultz already pointed out).

Danke an meiner Reporterin, XYZ

There are several problems with this. For example is “meiner" wrong in this context because “Reporterin" is female, also “Reporterin” is not the word you are looking for since it is used for journalism. I suggest one of the following.

Dank an meine Gutachterin, xyz

or a bit more formal

Dank gebührt meiner Gutachterin, xyz

Now back to your original question. I suggest something like

Dank an meine Gutachterin, xyz, die weder durch die Komplexität des französischen Eisenbahnnetzes noch der Verwaltung zu uns (? your ended your sentence so I don't know what would follow) navigierte.

Writing

der die Komplexität des französischen Eisenbahnnetzes und Verwaltung navigierte

sounds a bit incomplete to me. I would suggest an other construction for your sentence. But first let me fix the beginning of your sentence (like Carster Schultz already pointed out).

Danke an meiner Reporterin, XYZ

There are several problems with this. For example is “meiner" wrong in this context because “Reporterin" is female, also “Reporterin” is not the word you are looking for since it is used for journalism. I suggest one of the following.

Dank an meine Gutachterin, xyz

or a bit more formal

Dank gebührt meiner Gutachterin, xyz

Edit: After the edit of the original question and a complete sentence here is my edit answer.

Applying the French rule of masculine forms include feminine forms results in the German language with sentences that sound to a native speaker like something is missing and the sentence is just not rounded. But there are further problems with your sentence. Let me first fix it and then try to explain why.

Ein besonderer Dank gebührt der (or if you want it more personal replace „der“ with „meiner“) Zweitgutachterin (or in a less formal version „Gutachterin“), Frau Dr. xyz, die, trotz der Komplexität des französischen Bahnnetzes sowie der französischen Verwaltung, meiner Verteidigung der Dissertation beiwohnen konnte.

The word „navigierte“ is used in the wrong context here. “Navigieren” is more used for driving left and right, not for “found the way” like you want to use it here. Same with “besuchen” it’s more in the sense of visit an old friend. The way you want to use attend is that she managed to physical be there, so “beiwohnen” is the right choice here. Then there is the “Reporterin” thing you opened another question for that don’t really fit in here. And last but not least using “trotz” and “sowie” is a sort of enumeration that looses the stricter way you trying to avoid.