Hello, @JasonTseng
Thanks for the feedback.
Regarding to your questions:
Q1: "PCIe1 L1" means PCIe1 Lane1, right?
[C.Y] Yes
Q2: "PFE_MAC1_SGMII" means SGMII (PFE MAC1), right?
[C.Y] Yes
Q3: "SERDES S1 L0" means serdes1 lane0, right?
[C.Y] Seems confusion here, since only SERDES1_LANE1 could be configure to SGMII_PFE_MAC1.
But from the schematic, the PCIe1_lane1(or call it Serdes1_lane1) connect to the SGMII PHY via the connector, while the corresponding pins on connector are called serdes1_xx0xx, this maybe one possible reason that it is written as “SERDES S1 L0 (ENET AQR107) after the yellow arrow.
Whatever, from my opinion, you may refer to the following chart from the EVB UG to understand the connection for Serdes.

Hope it helps.
Best Regards
Chenyin