In Brazil the relation between university administration career and academic titulation isn´t a rule. Nowadays the prevalence of concepts like "professionalism" and "competitive edge", ally to privatization of superior education, have driven to focus in the management skills and not in the knowkledge about education.
Mrs./Miss/Mr. Illbeigi generally very interesting question because the requierments, particularly for Higer Educational Institutions in the European Union Countries are determined by the Higher-Educational-Law (HEL) macroframework and the rules determined within the frame of the academic autonomy of each of the Institutions. Even it has nuances in the Laws within the frame of each of the Federal States for example in Germany.
Furthermore it has different requierments for different academic administrative positions, but for eaxmple for Rector/President:
In Bulgarian (BG) HEL-BG §31(1) determined that the candidate should have 'habilitation', meaning not only to have 'PhD' degree, but in addition habilitation. The Universities' Academic Councils and Senats however restricted (according HEL-BG §19(1) for academic autonomy) to usually habilitation and holded 'full professor position' as academic-grad. In addition to administration experience as for example 'Vice-Rector' or 'Director of the research Institutes'. In addition obligatory the Rectors are usually candidates which have proven outstanding as possible high scientific profile according the employing conditions and possibilities in this Country. Because of the elected candidate according the HEL (BG §31(1)) should have work-contractfor academic position in the corresponding Unis.
In Germnay (GER) for example related HEL Arts. §15-§17, particularly for Nordrhein-Westfalen (NRW) they are joined with the 'President'-position, but they are applied equivalently for 'Rector'. Similar however the work-contract of the elected candidate is under W3-grad, meaning the highest academic (full professor) grad. Usually however W3-position is joined with Head-of-Department functions, on the other site it is also obligatory a 'habilitation' (HEL-GER-NRW §36(1) 4).
By contrast, the Bulgarian and like this in Brazil, from the available statement of Mr. Rodrigues, for Germany it has no obligation for outstanding own scientific/academic profile.
With one sentnce the answer of your question particularly for Gemany and Bulgaria for administrative academic positions Rector/President is generally: ''PhD grad+habilitation+administrative experience (both for GER and BG) + 'outstanding profesional achievements in the own field' (only for BG)''
While it does vary from country to another the vast majority require a PhD+ full professor rank and administrative experience for the position of president.