struct param {
uint256 amount;
uint256 percentageBonus;
}
struct offerings {
param proposed;
param received;
param accepted;
param rejected;
}
mapping(address => offerings) public offeringData;
Like this, you will be mapping each address to a structure with four fields (proposed, received... etc) each of these fields have two fields (amount and percentageBonus)
you can use it like this, assume the user address is A:
offeringData[A].proposed.amount
will give you the amount proposed by the user with address A.
offeringData[A].proposed.percentageBonus
give you the percentage bonus. Same for the other variables.
You can set these doing, for instance,: offeringData[A].proposed.amount = value
Hope this helps.