How did the Crusades lead to Europe’s “wider world view?”
First of all, please note that many scholars do not believe that the Crusades really did lead to Europeans having a "wider world view." Jackson Spielvogel, for example, says that there "may have been some broadening" of the way that the Europeans saw the world as the result of the Crusades. (Source, Spielvogel, Western Civilization 3rd Edition, page 354.) However, he argues, there was actually much more broadening of European world views through European contact with Muslims in Spain.
Of course, the Crusades are often said to have helped Europeans have a broader world view. The reason for this was that they exposed many more Europeans to the Muslim world. Since scientific learning and knowledge was very important in the Muslim world, this exposure changed European world views. The change was also heightened by trade. Trade between Europe and the Middle East was enhanced (though not started) by the Crusades.
Traditionally, then, the Crusades are said to have exposed Europeans to Muslim knowledge and culture, thus broadening their world views. However, there are scholars who take issue with this claim.