The PS Application provides reports that shows the financial indicators are project level (WBS Element).
The Financial Indicators include :

Access to the "PS - Project Costs" Application has to be requested (See Getting an account).
Access is managed at 2 levels, which you will need to precise when requesting the access :
Currently the WBP PS Application only contains data coming from the RCS System, so only the legal entities managed in WP1 SAP system will be included in this report.
The data is updated daily around ~4 am Paris Time.
All the queries for the PS Application can be found in the role "PS - Project Costs" (ZR_RCS_CA_M09) :

Here are the links to the detailed query documentations :
In some cases, a Purchase Order (PO) can be assigned to several costing elements (Cost Centers, WBS elements, Orders).
This happens in two ways :
In this case, the GR will be correctly split and the cost assigned to each element but as there will be only one invoice, SAP will not split the value of the invoice (Payable - FIAP) into each assigned element.
The result is that by default, the full amount of the invoice will be assigned on the first element found by SAP and the CASH will not reflect the reality.
In order to avoid this, the BW system will split the invoice by WBS/CostCenter/Order in the BW reports.
Case 1 - 1 PO with multiple items assigned to several elements - But 1 single invoice

In this case BW will split proportional the amount of the invoice by element. In this example, the CASH will reflect only 115$ on WBS1 even though the full value of the invoice (1160$) is assigned on WBS1 in SAP.
Case 2 - 1 PO with 1 item, 1 settlement rule with 2 objects, 1 invoice

BW will split the amount of the invoice based on the settlement rule.
"PEC" is the acronym for the french name "Prise En Charge", which translates into "Bearing of the costs". Meaning the Actual Costs of all goods/services received.
The "PEC" was used for Rhodia Legacy. It is replaced by the wording "Capital Spend".
CAPEX stands for Capital Expenditure. It is equal to the CASH (Out) when filtering on investments only.
CASH is short for "Cash Out", meaning the amount that has been paid (or received for invoicing WBS). It includes both "CAPEX" (Investment Cash Out" and "OTC" (One Time Costs - Non-investment cash out).