If each field needs a label directly to its left, you can add a child Container to the FormPanel with a layout of "column" or "hbox", either one depending on what you need to accomplish. "column" would work fine, although you have better auto-sizing functions (e.g., flex) with the "hbox" layout. You just need to set "hideLabel" on the Container. Then, inside of the Container you would add 3 more Containers, each with the layout of "form". Finally inside of each Container, you can add your fields with their labels set.
Otherwise, if they don't need a label directly to the left, and can either have a "collective" label or simply a single label, look into the CompositeField, which automatically lays out fields horizontally in an inner hbox container.