Lachlan Murdoch, who has been serving as a director at News Corp and 21st Century Fox, will work closely with senior management to develop global strategies and guide the overall corporate agenda, the company said in a statement on Wednesday.
source: http://mobile.reuters.com/article/topNews/idUSBREA2P0JQ20140326?irpc=932
My intuition is that it means: to help all problems related to the corporation be solved. Based on my perception, the word "agenda" has to do with "problems" ... the word " overall" just means "all"!