Q: How to write the methodology chapter as I couldn't contact anyone for interview?

Thank you for your question. Interviewing participants is just one of several ways to gather data for research. When participants are unavailable for surveys, authors may resort to other data sources, including previously published research (while citing sources that have been referred to, of course). Going through previous publications on the legal aspects of FDI (even if the study wasn’t conducted in the same area/country or differs in some aspect from your dissertation), especially the methodology sections of these papers, will give you an insight into how the methodology section is generally written for this area of study. As long as your sources of information are credible, and the methodology section appropriately defines the resources used, clarifies how they were obtained (and if they’ve been through any procedure), and explains the protocols, measures, statistical tests and calculations, this should suffice. I hope this helps and I wish you the very best for your dissertation!