Depending on your needs there are a few different tools:
1) You can place separators in your form that conditionally make certain sections of the form visible
2) dynamic READ PROTECT rules on certain attributes
3) On reference attributes, you can filter the items shown in the drop down. Filter is in the lower right of the screen where you specific the details of the reference attribute.
4) Plain Text attributes with a choice list can have "dynamic choices" specified.