Previously i worked on the project which used InfoPath form. The Form had many sections and each section had scrolling and lot of data. I needed to introduce accordion in the form. I needed to add buttons to show hide any section of the form so that user can focus on what is required. InfoPath is different than the normal JQuery accordion where you can hide or show any thing based on script or just CSS. In InfoPath you need to add behavior and Rules for each button and section which we want to hide or we want to use as changing behavior or variable. Following is the how i achieved it,
1- First thing first, add two picture buttons (Having up and down pictures).
2- Add Boolean variable ESShow and set its default value as 0 if you want to hide section when InfoPath form loads otherwise set its default value 1.