How do democratic governments-in-exile, such as the Rada of the Belarusian Democratic Republic, choose their members of government?

Question

Many governments-in-exile are relatively limited in time. For example, during World War II, occupied countries like The Netherlands had governments-in-exile. However, some exist for a long time. For example, the Rada of the Belarusian Democratic Republic has been a government-in-exile since 1919, almost 100 years, waiting for Belarussia to become a democracy.

How do democratic (or "democratic") governments-in-exile, such as the Rada of the Belarusian Democratic Republic, choose their members of government? For monarchies, the answer is quite clear: someone claims the throne and this is inherited as if they were actually in power. But in democracies, a government is normally formed after elections. Such elections are impractical for a government that has no control over any territory. Then how do they decide who is in the government-in-exile? Are there elections among some registry of the diaspora?

Answer 1

Not sure about other governments-in-exile, but BNR Rada has a charter published on their site. The election process is described there:

5. BNR President.
   22. The BNR President is the head of the BNR Rada.
   23. The BNR President is the highest representative of the BNR Rada and of the Belarusan nation. The BNR President is elected at the BNR Rada Session for a 6-year term.

The session is a biennial gathering of Rada members. The membership requirements are also in the charter:

2. The membership of BNR Rada.
   7. The BNR Rada is composed of Members of the Rada (MR) whose number shall not exceed 80 (eighty). Prospective members that are true to the Act of March 25 can be proposed by Belarusan political and civic organizations, as well as by informal independence-minded groups of Belarusans not fewer than 5 in number. Each proposed member must be recommended by at least two MRs. Such proposed membership along with the recommendation shall be sent to the BNR President or to the BNR Rada Executive Council for review. Approved candidates are confirmed by the BNR Rada Session. In case of exceptional need, the approved candidate may be confirmed by the BNR Rada Executive Council.

I'm not sure how strictly this process is followed in practice, but the process itself is clearly defined.

So, to answer your questions:

Then how do they decide who is in the government-in-exile? Are there elections among some registry of the diaspora?

In this case, only Rada members vote in the election. Rada is relatively small self-governing invite-only organization.