There exists by constitutional provision Council of State that advises the President. Council membership is by both election and appointment. There is also a Cabinet which is chaired by the President. By constitutional provision, a majority of Cabinet members must be appointed from among members of Parliament (The Legislature).
By constitutional provision, in the absence of the President, the Vice-President acts in his stead and in the absence of both the President and the Vice President, the Speaker of the House of Parliament takes over the mantle of State.