Who used the "Special seven tiered baskets" that "were employed to display the firstfruits"?

Question

The Temple Institute wrote,

"Likewise, pilgrims brought the firstfruits from their own fields and orchards, of the seven fruits of the land of Israel mentioned in Deuteronomy: Figs, grapes, dates, pomegranates, olives, wheat and barley."

Then on the next page, the Temple Institute put out an illustration of a seven-tiered basket:

Their explanation of the photo is as follows:

Special seven tiered baskets were employed to display the firstfruits. The fruits were arranged in ascending order of importance: the bottom basket contained barley. This was followed by wheat, olives, dates, pomegranates, and figs. A dove was set on the top.

My question:

Who used the "Special seven tiered baskets" that "were employed to display the firstfruits"? I can't tell, from their explanation, whether these "Special seven tiered baskets" were employed by the priests/Levites and/or the common observant Israelites? Who fashioned these "Special seven tiered baskets"? Were there only two in the Temple? Were there several? How many?

(I'm also interested in some details about the content and arrangement of these baskets and will post additional questions about those, depending on what I learn from answers to this question.)

Answer 1

Their source would appear to be Rambam Hilchot Bikkurim 3:7:

The first fruits must [be brought in] a container, as [it] states: 'And you shall place them in a container.' The most preferable way of performing the mitzvah is to bring each type of fruit in a separate container. If one brings them [all] in one container, he has fulfilled his obligation. [Even in such an instance,] he should not bring them mixed together. Instead, he should bring the barley below, wheat on top of it, olives on top of it, dates on top of them, pomegranates on top of them, and figs on the top of the container. There should be a substance, e.g., palm leaves, wild grass, or leaves, or the like, that intervenes between each type of produce. One should surround the figs with clusters of grapes from the outside.

(Touger translation)

(Rambam's source is Tosefta Bikkurim 2:8.)

From the context ('bringing the first fruits'), it seems clear to me that he is discussing the manner in which the pilgrims would bring the bikkurim to the Temple, rather than a method by which the priests would display them.